Plug and receptacle connectors must often be mated in a blind space, such as where a plug-in module has a plug connector at its rear. When the module is inserted rearwardly into a deep slot in a frame, the plug connector at the rear of the module must mate with a receptacle connector on the frame at the rear of the slot thereof. The most common practice is to provide a separate guide plate with rearwardly-projecting pins that assure accurate alignment of the connectors as they approach each other. However, the guide plate takes up additional room around the plug connector and constitutes an added expense. It may be noted that connectors commonly used include an insulative body with small holes for holding ordinary signal contacts and larger holes for holding coaxial contacts. A connection system which provided guide pins for accurately aligning a pair of connectors as they approached one another to mate, which avoided the need for extra space around the connectors to accommodate such guide pins, which used such guide pins to connect the ground planes of the circuitry coupled to the two connectors, and which enabled such guiding function to be easily added to existing connector designs, would be of considerable value.